#!/usr/bin/env python
#coding=utf-8 

# 简单猜数字升级版本

from operator import add, sub
from random import randint, choice

ops = {'+':add, '-': sub}
MAXTRIES = 2

def doprob():
	op = choice('+-')
	nums = [randint(1,10) for i in range(2)]
	nums.sort(reverse = True)
	ans = ops[op](*nums)  # Core
	pr = '%d %s %d='%(nums[0], op, nums[1])
	oops = 0
	while True:
		try:
			if int(raw_input(pr)) == ans:
				print 'correct'
				break
			if oops == MAXTRIES:
				print 'answer\n%s%d'%(pr, ans)
			else:
				print 'incorrect... try angain'
				oops += 1
		except (KeyboardInterrupt, \
			EOFError, ValueError):
			print 'invalid input... try again'
def main():
	while True:
		doprob()
		try:
			opt = raw_input('Again? [y]').lower()
			if opt and opt[0] == 'n':
				break
		except (KeyboardInterrupt, EOFError):
			break

if __name__ == '__main__':
	main()